List of top Mechanical Engineering Questions

An element is subjected to a tensile stress of 60 MPa and a shear stress of 40 MPa. If the material has the yield strength obtained in a simple tensile test is 320 MPa, the factor of safety based on maximum principal stress theory is
In the multiple disc clutch, if there are six discs on the driving shaft and five discs on the driven shaft, then the number of pairs of contact surfaces will be
Two mating spur gears have 36 and 108 teeth, respectively. The pinion rotates at 1200 rpm and transmits a torque of 20 Nm. The torque transmitted by the gear is
In eccentric loading of welds, the stress which vary from point to point as proportional to its distance from the centre of gravity, is known as:
The area under the turning moment diagram represents
Whirling speed of a shaft coincides with the natural frequency of its:
A 10 kg mass is supported on a spring of stiffness 4 kN/m and has a dashpot which produces a resistance of 20 N at a velocity of 0.25 m/s. The damping ratio of the system is:
In a simple gear train, if the number of idler gears is odd, then the direction of motion of the driven gear will be:
The natural frequency of a spring-mass system is 2 Hz. When an additional mass of 1 kg is added to the original mass \( m \), the natural frequency is reduced to 1 Hz. The original mass \( m \) is
The direction of the linear velocity of any point on the kinematic link relative to any other point on the same kinematic link is

The number of degrees of freedom of the mechanism shown in Figure is

Maximum shear stress developed on the surface of a solid circular shaft under torsion is 240 MPa. If the shaft diameter is doubled, then the maximum shear stress developed corresponding to the same torque will be:
In a four-bar mechanism ABCD, the link lengths are given: AB = 800 mm, BC = 100 mm, CD = 400 mm, DA = 700 mm. If the mechanism is a double crank mechanism then the fixed link should be
A column fixed at one end and free at the other end buckles at a load P. Now, both the ends of the column are fixed. What is the buckling load for these end conditions?
A bar of length \( L \), area of cross-section \( A \), is subjected to a tensile force \( P \). If \( E \) is the Young's modulus of the bar, the strain energy \( U \) stored in the body is:
The total number of instantaneous centres for a mechanism of \( n \) links are:
A slider sliding at 100 mm/s on a link which is rotating at 60 rpm is subjected to Coriolis acceleration of magnitude:
If the shear force diagram for a beam is a triangle with the length of the beam as its base, the beam is
The ratio of area under the bending moment diagram to the flexural rigidity between two points of a beam gives the change in
A steel rod of diameter 10 mm and 1 m long is heated from 20°C to 120°C, its coefficient of thermal expansion \( \alpha = 12 \times 10^{-6} / \text{K} \) and Young’s Modulus \( E = 200 \, \text{GPa} \). If the rod is free to expand, the thermal stress developed in it is
Which of the following strain mainly represents the change of shape?
A beam has rectangular section with width and depth as 100 mm \( \times \) 200 mm. If it is subjected to maximum bending moment of 40 kN-mm, then the minimum bending stress developed would be
State of stress at a point of a loaded component is given by normal stresses \( \sigma_x = 30 \, \text{MPa} \), \( \sigma_y = 18 \, \text{MPa} \), and shear stress \( \tau_{xy} = 8 \, \text{MPa} \). What are the principal stresses?

A solid cylinder of weight \( W = 100 \, \text{N} \) and radius \( r = 0.5 \, \text{m} \) is pulled along a horizontal plane by a horizontal force \( P = 90 \, \text{N} \) applied to the end of the string wound around the cylinder. What is the angular acceleration of the disc? Assume \( g = 10 \, \text{m/s}^2 \).

A 160 g cricket ball is moving with a speed of 20 m/s. What force is required to stop the ball in 0.2 seconds?